Draft and Final RFP for Gateway logistics/cargo services

[ThomasGadd]

SpaceX can use Falcon Heavy to launch Dragon in a fast trajectory to Gateway' s NRHO orbit... but can' t do braking only with Dracos. So it is supposed SuperDracos would be needed.

The braking does not need to be instantaneous - it's not landing on the moon.
The Draco thrusters already do ~250m/s or so per mission, and there are 18 of them - 1200N in each axes + and -.

At 10 tons mass, 1200N leads to needing around a 400s burn, which is for these purposes instantaneous.

The lifetime of the Draco engines isn't really in question either, because if you have to, you can use more than one axes (200s on +z, flip and 200s on -z).

It is at most a modest increment over the total nominal mission firing time to ISS.
Superdracos are pointless weight for this.

It looks Dragon 2 cargo is close to the minimum required payload (3,400 kg). 
If it can't meet that requirement, missions are not always at max. For the few that are they use a stripped (heat shield and parachutes)  non-reusable Dragon. 

[gongora]

It looks Dragon 2 cargo is close to the minimum required payload (3,400 kg). 
If it can't meet that requirement, missions are not always at max. For the few that are they use a stripped (heat shield and parachutes)  non-reusable Dragon.

The requirement is for that mass at a specified packing density.  Dragon 2 doesn't meet it because of volume.

[ThomasGadd]

It looks Dragon 2 cargo is close to the minimum required payload (3,400 kg). 
If it can't meet that requirement, missions are not always at max. For the few that are they use a stripped (heat shield and parachutes)  non-reusable Dragon.

The requirement is for that mass at a specified packing density.  Dragon 2 doesn't meet it because of volume.

Right... thanks.

[pochimax]

It looks Dragon 2 cargo is close to the minimum required payload (3,400 kg). 
If it can't meet that requirement, missions are not always at max. For the few that are they use a stripped (heat shield and parachutes)  non-reusable Dragon.

The requirement is for that mass at a specified packing density.  Dragon 2 doesn't meet it because of volume.

It is a very interesting comment.

I suppose NASA would know it, so it implies NASA WANTS SpaceX to evolve its Dragon V2 into a bigger Lunar Dragon type.

Problem is how expensive that evolution will be.

[A_M_Swallow]

It looks Dragon 2 cargo is close to the minimum required payload (3,400 kg). 
If it can't meet that requirement, missions are not always at max. For the few that are they use a stripped (heat shield and parachutes)  non-reusable Dragon.

The requirement is for that mass at a specified packing density.  Dragon 2 doesn't meet it because of volume.

It is a very interesting comment.

I suppose NASA would know it, so it implies NASA WANTS SpaceX to evolve its Dragon V2 into a bigger Lunar Dragon type.

Problem is how expensive that evolution will be.

As soon as a crew Dragon is sent to the Gateway someone will want to put a crew in a future one.

[jadebenn]

As soon as a crew Dragon is sent to the Gateway someone will want to put a crew in a future one.

Nah, I don't think there's much of a market for a one-way trip.

[speedevil]

As soon as a crew Dragon is sent to the Gateway someone will want to put a crew in a future one.

Nah, I don't think there's much of a market for a one-way trip.

Crew dragon to NHRO, with the ability to rendevous with gateway, and return with crew would work pretty simply.
Requiring crew and cargo both ways on the same trip would make it rather heavier and with considerably more design time.

[jadebenn]

Crew dragon to NHRO, with the ability to rendevous with gateway, and return with crew would work pretty simply.
Requiring crew and cargo both ways on the same trip would make it rather heavier and with considerably more design time.

How? Where are you getting the Delta-V for that?

A one way trip by Dragon should be feasible (though not for living cargo - would need beefier life support) but once Dragon is in NRHO, there's absolutely no way it's getting back.

[A_M_Swallow]

Crew dragon to NHRO, with the ability to rendevous with gateway, and return with crew would work pretty simply.
Requiring crew and cargo both ways on the same trip would make it rather heavier and with considerably more design time.

How? Where are you getting the Delta-V for that?

A one way trip by Dragon should be feasible (though not for living cargo - would need beefier life support) but once Dragon is in NRHO, there's absolutely no way it's getting back.

That is where in-flight refuelling of the crew Dragon at the Gateway comes in.

[su27k]

Crew dragon to NHRO, with the ability to rendevous with gateway, and return with crew would work pretty simply.
Requiring crew and cargo both ways on the same trip would make it rather heavier and with considerably more design time.

How? Where are you getting the Delta-V for that?

A one way trip by Dragon should be feasible (though not for living cargo - would need beefier life support) but once Dragon is in NRHO, there's absolutely no way it's getting back.

There're low energy trajectories from LEO to NRHO that only costs 20 m/s or so delta-v after TLI, and takes about 4 ~ 5 months. A uncrewed Dragon can use this trajectory to get to Gateway and park there waiting for the crew, while still have enough propellant left for a crewed fast return to Earth.

[speedevil]

There're low energy trajectories from LEO to NRHO that only costs 20 m/s or so delta-v after TLI, and takes about 4 ~ 5 months. A uncrewed Dragon can use this trajectory to get to Gateway and park there waiting for the crew, while still have enough propellant left for a crewed fast return to Earth.

An interesting question might be if you could use two ~unmodified (no pressure hull enlargement or heatshield alterations) crew dragons per nominal one cargo delivery.
If reuse is plausible.
Split the mass over them both to ease launches.

[gongora]

Maybe ya'll should start a thread for theoretical Dragon spinoffs.

[ThomasGadd]

Maybe ya'll should start a thread for theoretical Dragon spinoffs.

That would be interesting what could be done with Dragon with reasonable time and costs before SS.

[pochimax]

Yesterday, october 16, was the last day for bidding in this RFP. Now is closed.

Really looking forward to know  what has offered SpaceX in order to resuply Gateway. And its cost.

[ncb1397]

We submitted our supply spacecraft proposal to @NASA for its Gateway program. Our design uses low-risk, high-capability components to reliably take food, water and supplies to the astronauts carrying out #Artemis’s Moon mission in 2024.

www.twitter.com/BoeingSpace/status/1184614647443480576

Not sure exactly how this thing pictured is supposed to work....

edit: I found a better picture with more detail of a ground mockup....

[GWH]

Isn't that there habitat prototype though?
Looks just like it:
https://www.nasa.gov/centers/marshall/nasa-aids-testing-of-boeing-deep-space-habitat-ground-prototype-in-alabama.html

Unless their proposal is just to send it up with Orion on SLS+EUS 

[jadebenn]

I think Boeing's animation was just meant to be a generic render of Gateway. I doubt they'd unveil their cargo-craft like that.

[pochimax]

This could be the look of the "Lunar Cygus". In this image, attached to miniGateway.

Different solar panels than Cygnus and HALO.

[pochimax]

From a Boeing Space twit, is this (bottom left) its version of lunar cargo ship?

Correct me but I am seeing 3 components:

1. Cylindrical cargo module (ISS node derived?) as its diameter seems bigger than HALO.
2. Capsule (for samples return to Earth?)
3. SEP tug? reusable SEP tug? reusable refuelable SEP tug?  Two launches on a Vulcan?



https://mobile.twitter.com/BoeingSpace/status/1192908333478502406

[brickmack]

From a Boeing Space twit, is this (bottom left) its version of lunar cargo ship?

Correct me but I am seeing 3 components:

1. Cylindrical cargo module (ISS node derived?) as its diameter seems bigger than HALO.
2. Capsule (for samples return to Earth?)
3. SEP tug? reusable SEP tug? reusable refuelable SEP tug?  Two launches on a Vulcan?

Yes, thats their cargo vehicle. I don't think your interpretation is correct though. Heres http://www.madeinalabama.com/assets/2019/06/BoeingGatewayConcept-April192-1.jpg an older render showing it as well. Definitely some design changes, but broadly the same vehicle.

That render shows what looks like 6 chemical main engines. If it was SEP, they'd need much bigger solar arrays to get the vehicle to Gateway in a reasonable amount of time (thats the max load case that all the PPE bids sized their solar arrays for, and this cargo vehicle would have a higher payload mass and an equal or shorter travel time than the PPE). My understanding was that most of the PPE bidders would be bidding for GLS as well with a modified version, apparently Boeing was not among them (perhaps they thought it unlikely that more than one PPE derived cargo vehicle would be viable given the long travel time).

The capsule seems to just be an (oddly long?) endcone on the pressurized section.

Probably would be either a dual-launch Vulcan with refueling, or another SLS